ENH: new spread_by_counts()
use spread_by_counts() in fit_von_mises.py, ex_fit_vonmises.py
ENH: add bins argument to VonMisesMixture.plot_dist(), use it
ENH: new Struct class for pretty printing of object attributes
inherit GaussianKDE, VonMisesMixture also from Struct
fit_von_mises.py: new --spread-data option
REF/TST: add tests for fit method, fix integer division in fit_ls,
TST: add test for normalize_params
Merge branch 'updates'